Diagnostic system and method for home appliance

ABSTRACT

A diagnostic system and method for a home appliance is provided. When the home appliance outputs product information as a sound signal, a service center remotely performs fault diagnosis of the home appliance by receiving the sound signal, detecting the product information from the sound signal, checking the state of the home appliance using diagnostic data included in the product information to determine whether the home appliance is out of order, determining, when a door error has occurred, a cause of the door error, and deriving a solution to the door error. Upon deriving a diagnosis result through the fault diagnosis of the home appliance, the service center immediately notifies the user of the diagnosis result and may dispatch a service technician or may provide the user with a solution to allow the user to easily fix the fault.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Korean PatentApplication No. 10-2009-0071048, filed on Jul. 31, 2009 in the KoreanIntellectual Property Office, and U.S. Provisional Patent ApplicationNo. 61/230,591 filed on Jul. 31, 2009 in the USPTO, the disclosure ofwhich is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to a diagnostic system and method for ahome appliance, and more particularly to a home appliance diagnosticsystem and method for performing state inspection and fault diagnosis ofa home appliance based on product information of the home appliance,which is output as a sound signal, to facilitate after-sale service forthe home appliance.

2. Description of the Related Art

In operation, a home appliance stores values set for execution of theoperation, information generated during the operation, faultinformation, etc. Particularly, in the event of a fault, the homeappliance outputs a predetermined alarm, thereby enabling the user torecognize the state of the home appliance. The home appliance may outputdetailed fault information through its output device, for example, adisplay device or lamp, as well as simply notifying the user ofcompletion of an operation or occurrence of a fault.

On the other hand, in the event of a fault in the home appliance, theuser may utilize an after-sale service of calling a service center toask advice on the state of the home appliance or request a servicetechnician for the home appliance.

In this case, the home appliance generally outputs fault informationsimply or as a code value that cannot be understood by the user. Forthis reason, the user may have difficulty in coping with the fault inthe home appliance and in accurately communicating the state of the homeappliance to the service center even though contacting the servicecenter. Consequently, when a service technician visits the user's home,a lot of time and cost may be taken for the service technician to repairthe home appliance due to lack of accurate prior knowledge as to thestate of the home appliance. For example, provided that a part requiredfor repair of the home appliance is not prepared in advance, the servicetechnician will have the inconvenience of re-visiting the user's home,resulting in an increase in repair time.

In order to solve the above problem, the home appliance may be connectedto a server of the service center via a communication unit. However, inthis case, it is necessary to construct a communication network.

With technological development, a fault may be remotely diagnosed over atelephone network.

European Patent No. 0510519 discloses a technique for transmitting faultinformation of a home appliance to a service center via a modemconnected to the home appliance over a telephone network. However, thistechnique requires continuous connection of the modem to the homeappliance. Particularly, in the case where the home appliance is alaundry treatment machine that is usually installed outdoors, a spatialrestriction may be imposed on connecting the laundry treatment machineto the telephone network.

U.S. Pat. No. 5,987,105 discloses a technique for converting faultinformation of a home appliance into a sound signal of an audiblefrequency band and transmitting the sound signal to a service centerover a telephone using a telephone network. Signal interference mayoccur depending on an ambient environment in the course of convertingthe fault information of the home appliance into the sound signal of theaudible frequency band and then transmitting the sound signal to areceiver of the telephone. In addition, data may be lost according tocharacteristics of the telephone network during the transmission of thesound signal over the telephone network.

In the case of U.S. Pat. No. 5,987,105 described above, the size of onesymbol representing 1 bit which is one information unit is 30 ms and anindependent frequency is used for each bit in order to prevent data lossand to correctly communicate product information.

However, the conventional system has suggested no detailed scheme forperforming diagnosis on the state of the home appliance.

There is a need to suggest a detailed scheme not only for outputtingproduct information using a sound signal but also for performing faultdiagnosis using data included in the product information.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the aboveproblems, and it is an object of the present invention to provide a homeappliance for outputting a sound signal including product information tofacilitate fault diagnosis using the sound signal, and a diagnosticsystem for the home appliance.

It is another object of the present invention to provide a diagnosticsystem and method for a home appliance wherein the state of the homeappliance is determined and a fault thereof is diagnosed using productinformation extracted from an output sound signal to achieve correctfault diagnosis for the home appliance and also to enable rapidafter-sale service for the home appliance.

In accordance with an aspect of the present invention, the above andother objects can be accomplished by the provision of a diagnosticmethod for a home appliance diagnostic system, the method includingreceiving a sound signal output from a home appliance and extractingproduct information about the home appliance from the sound signal,analyzing the product information and determining, when an error code isset in the product information, whether the error code corresponds to adoor error associated with a door of the home appliance, diagnosingfault of the home appliance by determining, when the error codecorresponds to the door error, whether the door or a program of the homeappliance is out of order using diagnostic data associated with the dooramong a plurality of diagnostic data included in the productinformation, and deriving a diagnosis result by deriving a solutioncorresponding to a cause of the door error, the cause being obtainedaccording to the fault diagnosis.

In accordance with another aspect of the present invention, there isprovided a home appliance diagnostic system including a home appliancefor outputting product information required for fault diagnosis as asound signal, a diagnostic server for receiving the sound signal,deriving a state, a fault, and a fault cause of the home appliance, andderiving, as a diagnosis result, a solution to the fault, and a portableterminal for receiving the sound signal output from the home applianceand transmitting the sound signal to the diagnostic server through acommunication network, wherein the diagnostic server determines, when anerror code is set in the product information extracted from the receivedsound signal, whether the error code corresponds to a door errorassociated with a door of the home appliance based on the productinformation, and diagnoses fault of the home appliance by determining,when the error code corresponds to the door error, whether the door or aprogram of the home appliance is out of order using diagnostic dataassociated with the door among a plurality of diagnostic data includedin the product information, and then derives a solution to the fault ofthe home appliance.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a schematic view showing the configuration of a home appliancediagnostic system according to an embodiment of the present invention;

FIG. 2 is a perspective view showing the configuration of a homeappliance according to an embodiment of the present invention;

FIG. 3 is a block diagram showing a configuration for control of a homeappliance in the home appliance diagnostic system of FIG. 1;

FIG. 4 is a block diagram of a diagnostic server of a service center inthe home appliance diagnostic system illustrated in FIG. 1;

FIG. 5 illustrates a method for encoding product information of a homeappliance and structures of a digital signal encoded accordingly;

FIG. 6 illustrates a structure of the digital signal and a method forencoding the digital signal;

FIG. 7 is a waveform diagram illustrating frequency conversion of amodulator;

FIG. 8 is a flow chart illustrating a diagnostic method for a homeappliance diagnostic system according to the present invention;

FIG. 9 is a flow chart illustrating a diagnostic method using productinformation in a home appliance diagnostic system of the presentinvention;

and

FIG. 10 illustrates exemplary fault diagnosis results using productinformation in a home appliance diagnostic system of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

FIG. 1 is a schematic view showing the configuration of a home appliancediagnostic system according to an embodiment of the present invention.

Referring to FIG. 1, a home appliance of the present invention isconfigured in such a manner that, when a home appliance 101 in each homeoutputs information about the operation thereof in the form of a soundsignal, the sound signal, which includes product information, is inputto a portable terminal such as a mobile phone or a telephone and is thentransmitted to a service center 200 over a telephone network so that adiagnostic server in the service center 200 may diagnose the state ofthe home appliance 101 to determine whether the home appliance 101 isout of order.

The home appliance diagnostic system includes the home appliance 101 andthe service center 200 for monitoring the state of the home appliance101 and diagnosing the fault of the home appliance 101. The servicecenter 200 includes the diagnostic server having home applianceinformation and a diagnosis program.

The home appliance 101 includes a display device 118 for displayingpredetermined data. The display device is a light emitter such as alight emitting diode (LED), a liquid crystal display (LCD) or an organicelectro-luminescent (EL) display, and visually displays stateinformation or fault information of the home appliance 101. The homeappliance 101 further includes a sound output device 160 for outputtinga sound signal. The sound output device 160 reproduces and outputsinformation about the operation, state or fault of the home appliance101 as a predetermined sound signal.

When the home appliance 101 malfunctions or operates abnormally, itnotifies the user of occurrence of a fault by outputting an error codethrough the display device 118 or outputting an alarm sound through thesound output device 160 (S1).

Here, the home appliance 101 stores product information includingoperation information, fault information, and user information.

The user confirms information of the home appliance 101 displayed on thedisplay device of the home appliance 101 and then controls the operationof the home appliance 101 or requests repair of the home appliance 101from the service center 200. At this time, the user may contact theservice center 200 to notify the service center 200 that a fault hasoccurred in the home appliance 101 and ask advice on the fault (S2).

In the case where the user connects to the service center 200 andmanipulates a selector (not shown) of an input device (not shown) in thehome appliance 101 in response to a request from the service center 200(S3), the home appliance 101 converts the product information into apredetermined sound signal and outputs the sound signal through thesound output device 160. The sound signal including the productinformation, output in this manner, is transmitted to the service center200 over a communication network (S4).

At this time, the user may notify the service center 200 of modelinformation and fault symptoms of the home appliance 101 and place aportable terminal 80 such as a mobile phone or a telephone close to asounding portion of the home appliance 101, that is, the sound outputdevice 160 during the call with the service center 200 to transmit thesound signal including the product information of the home appliance 101to the service center 200. In this manner, the user may transmit thesound signal including the product information of the home appliance 101to the service center 200 using portable terminal 80 such as a telephoneor a mobile phone to request an after-sale service (A/S) for the homeappliance 101.

The service center 200 receives the sound signal output from the homeappliance 101 over a communication network connected thereto, forexample, a telephone network, and checks the product state of the homeappliance 101 based on the received sound signal to diagnose whether thehome appliance 101 is out of order (S5).

Based on a result of the diagnosis, the service center 200 dispatches aservice technician 93 to the user's home to provide a service suitablefor the product state and fault diagnosis of the home appliance 101(S6). In step S6, the diagnosis result may be transmitted to a terminalof the service technician 93 so that he/she may fix the home appliance101.

In addition, the service center 200 may connect with the user throughthe communication network to transmit the diagnosis result to the userin the form of a voice through a customer service agent or in the formof predetermined data (S7).

Therefore, when the user connects to the service center 200 through acommunication network, for example, a telephone network, the diagnosticsystem can accurately determine the state of the home appliance 101based on a sound signal, thereby providing rapid service and alsoallowing the user to easily check the state of the home appliance.

Although the home appliance 101 of the present invention willhereinafter be described for illustrative purposes as being a laundrytreatment machine, the present invention is not limited thereto. Rather,it is to be clearly understood that the present invention is applicableto all home appliances including TVs, air conditioners, refrigerators,electric rice cookers, and microwave ovens. In the followingdescription, a telephone network or a mobile communication network isused as an example of the communication network and a telephone or amobile phone is used as an example of the portable terminal 80.

The home appliance 101 is constructed as described below to outputproduct information as a sound signal.

FIG. 2 is a perspective view showing the configuration of a homeappliance according to an embodiment of the present invention.

A description will hereinafter be given of a laundry treatment machineas an example of the home appliance.

Referring to FIG. 2, the laundry treatment machine 101, which is thehome appliance of the present invention, includes a cabinet 111, a tub122 disposed inside the cabinet 111 for washing laundry, a motor (notshown) for driving the tub 122, a wash water supply (not shown) forsupplying wash water to the tub 122, and a drainage device (not shown)for draining the wash water externally after the laundry is washed.

The cabinet 111 includes a cabinet body 112, a cabinet cover 113 coupledto a front side of the cabinet body 112, a control panel 116 disposedover the cabinet cover 113 for controlling the operation of the laundrytreatment machine 101, and a top plate 115 disposed over the controlpanel 116 and coupled to the cabinet body 112. The cabinet cover 113includes a hole (not shown) for putting in or taking out the laundrytherethrough, and a door 114 for pivotally moving to open/close thehole.

The control panel 116 is provided with an input device including amanipulator 117 having a plurality of manipulating keys for manipulatingthe laundry treatment machine 101, a sound output device 160 foroutputting a sound signal indicative of the operating state of thelaundry treatment machine 101, and a display device 118 for displayingthe operating state of the laundry treatment machine 101 in the form oftext, a numeral, a special symbol, an image, or the like. In the inputdevice, the manipulator 117 may be configured with an input unit forapplying a certain signal by push, contact, pressure, rotation, or thelike, such as a key, a button, a switch, a rotary switch, or a touchinput unit.

When the user has manipulated a selector in the control panel 116, thelaundry treatment machine 101 receives a smart diagnosis mode commandand a signal output command, converts product information into a digitalsignal in a predetermined format, and provides the digital signal to amodulator (not shown). As the modulator operates according to thedigital signal, a predetermined sound signal is output through the soundoutput device 160.

The sound output device 160 is provided at a rear side of the controlpanel 116 to output a sound signal from the inside of the control panel116. The sound output device 160 is spaced apart from the manipulator117, a selector 130 or a sound output hole 119 by a predetermineddistance so that it can be protected from water or foreign substancesincoming from the outside.

The sound signal output from the sound output device 160 is externallyemitted through cracks of portions of the control panel 116, in whichkeys of the manipulator 117 or selector 130 are formed, along a soundpath or sound guide portion formed at the rear side of the control panel116. Alternatively, in the case where the separate sound output hole 119is provided, the sound signal output from the sound output device 160may be externally emitted through the sound output hole 119.

Here, it is preferable that the keys of the manipulator 117 or selector130 be constructed so as to enlarge the gap between the control panel116 and each of the keys or to permit an internal sound to be emittedexternally when pressed.

The sound output device 160 may include at least one sound outputdevice.

For example, in the case where the sound output device 160 includes twosound output devices, one of the sound output devices may output a soundsignal of a combination of predetermined frequencies including productinformation of the home appliance and the other may output an effectsound or alarm sound of the home appliance and an indication soundindicative of the start or end of the output of the sound signalincluding the product information.

The sound signal output from the sound output device 160 is transmittedto the service center 200 through the portable terminal 80, connected toa communication network. Here, the communication network may be, forexample, a telephone network or mobile network, and the portableterminal 80 may be, for example, a telephone or mobile phone.

The service center 200, which includes the diagnostic server, receivesthe sound signal output from the laundry treatment machine 101 andanalyzes the received sound signal, so as to acquire operationinformation and fault information of the laundry treatment machine 101.As a result, the service center 200 transmits a countermeasure against afaulty operation of the laundry treatment machine 101 to the user ordispatches a service technician to the user's home.

FIG. 3 is a block diagram showing a configuration for control of a homeappliance in the home appliance diagnostic system of FIG. 1.

The home appliance 101 configured as stated above has a controlconfiguration for performing a washing mode, a rinsing mode, aspin-drying mode, etc. for laundry within the home appliance 101,processing data generated during the operation of the home appliance101, and, when a smart diagnosis mode is set based on an input of aselector, generating product information including data of the homeappliance 101 in the form of a digital signal of a predetermined formatand outputting a predetermined sound signal based on the digital signal.

Referring to FIG. 3, the home appliance 101 includes an input device125, a sensing device 170, a memory 145, a storage device 146, a driver180, a modulator 150, the sound output device 160, and a controller 140for controlling the entire operation of the home appliance 101.

The input device 125 is provided with at least one input unit forinputting a predetermined signal or data to the home appliance 101according to a user manipulation. The input device 125 includes themanipulator 117 and the selector 130.

The selector 130 has at least one input unit. Upon selection of thesmart diagnosis mode, the selector 130 applies a signal output commandto the controller 140 so that product information is output in the formof a predetermined sound signal through the sound output device 160.

The selector 130 may be provided with input units separate from those ofthe manipulator 117. Alternatively, the manipulator 117 may include twoor more input units that may operate or be recognized as the selectorwhen manipulated simultaneously, or a specific input unit that mayoperate or be recognized as the selector when manipulated consecutivelyor for a predetermined time or more.

As the smart diagnosis mode is entered, the selector 130 turns on/offthe sound output device 160. That is, when the signal output command isinput by the selector 130, a digital signal including productinformation is output in the form of a predetermined sound signal inresponse to a control command from the controller 140. At this time, thesound output device 160 operates to output the sound signal.

The manipulator 117 receives data such as an operation course oroperation setting according to the operation of the home appliance 101and applies the received data to the controller 140. The manipulator 117also receives settings related to sound signal output. That is, themanipulator 117 receives values for setting a sound signal outputmethod, the level of a sound signal to be output, etc.

The input device 125 including the selector 130 and the manipulator 117may be configured to include buttons, a dome switch, a touch pad (staticpressure/capacitance), a jog wheel, a jog switch, a finger mouse, arotary switch, a jog dial, or the like. Any device may serve as theinput device 125 so long as it generates predetermined input data by amanipulation such as push, rotation, pressure or contact.

The sensing device 170 includes at least one sensor for sensing atemperature, a pressure, a voltage, current, the level of water, thenumber of rotations, or the like, and applies sensed or measured data tothe controller 140. For example, when water is supplied or drained to orfrom the laundry treatment machine, the sensing device 170 may measurethe level of the water, the temperature of the supplied water, and therotation speed of the tub or drum. The sensing device 170 includes atleast one temperature sensing device (not shown).

The driver 180 controls driving of the home appliance 101 in response toa control command from the controller 140 such that the home appliance101 performs a set operation. Therefore, the laundry treatment devicewashes laundry by performing a series of modes including a washing mode,a rinsing mode and a spin-drying mode. The driver 180 includes a motorcontroller (not shown) for applying an operation control signal to themotor.

For example, in the case of the laundry treatment machine, the driver180 may drive a motor that rotates the tub or drum, and control theoperation of the motor to wash soiled laundry through rotation of thetub or drum. Also, the driver 180 may control a valve in response to acontrol command from the controller 140 to supply or drain water.

The memory 145 stores control data for controlling the operation of thehome appliance 101, reference data used during the control operation ofthe home appliance, and the like.

The memory 145 includes all data storage units including a read onlymemory (ROM) or electrically erasable programmable ROM (EEPROM) forstoring control data for the home appliance. The storage device 146 is abuffer for the controller 140 that temporarily stores data. The storagedevice 146 may be, for example, a dynamic random access memory (DRAM) orstatic RAM (SRAM). As needed, the storage device 146 may be incorporatedinto the controller 140 or memory 145.

While the home appliance 101 performs a desired operation, the memory145 stores operation information including operating state datagenerated during the operation and set data input by the manipulator 117such that the home appliance 101 performs the desired operation, usageinformation including the number of occurrences of a specific operationin the home appliance 101 and model information of the home appliance101, and fault information including information about the cause orposition of a fault when the home appliance 101 malfunctions.

The controller 140, when a signal for smart diagnosis mode entry isinput from the selector 130, fetches product information stored in thememory 145 or storage device 146, generates a digital signal of apredetermined format from the product information and applies thedigital signal to the modulator 150. Also, as the selector 130 ismanipulated, the controller 140 controls the sound output device 160 tooperate it.

The controller 140 includes a main controller 141 for controlling a flowof data being input or output to or from the home appliance 101,generating and applying a control command based on data input from thesensing device 170, or providing sensed data to the driver 180 tocontrol the driver 180 to operate the home appliance 101, and an encoder142 for converting product information into a digital signal of apredetermined format in response to an input of the selector 130 suchthat a sound signal based on the digital signal is output.

The main controller 141, when the smart diagnosis mode is entered inresponse to the input of the selector 130, outputs a start soundindicating the start of the smart diagnosis mode through the soundoutput device 160 and displays predetermined data indicating theexecution of the smart diagnosis mode through the display device 118.

Also, when a digital signal generated by the encoder 142 is applied tothe modulator 150 and a sound signal is thus output through the soundoutput device 160, the main controller 141 controls the sound outputdevice 160 to output a predetermined indication sound before and afterthe output of the sound signal. The indication sound before the outputof the sound signal may be omitted as needed.

On the other hand, in the case where the sound output device 160includes two or more sound output devices, the main controller 141 maycontrol the sound output devices to output the indication sound and thesound signal including the product information through different ones ofthe sound output devices, respectively.

Upon entry into the smart diagnosis mode, the main controller 141disables the manipulator 117 except for a power key and the selector 130and controls the sensing device 170 and the driver 180 to make the homeappliance 101 discontinue all other operations.

Also, when any one manipulating key of the manipulator 117 for settingof the operation of the home appliance 101 is input after power input,the main controller 141 does not start the smart diagnosis mode eventhough the selector 130 is input. Particularly, in the case where theselector 130 is not provided separately and an input of a combination oftwo or more of a plurality of manipulating keys of the manipulator 117is recognized as the input of the selector 130, the main controller 141starts the smart diagnosis mode only when the selector 130 is input by aspecified key combination immediately without any other input after theinput of the power key.

That is, the setting of the operation of the home appliance by themanipulator 117 is considered to indicate that the user has no intentionof entering the smart diagnosis mode, and the main controller 141 thusdoes not enter the smart diagnosis mode. Also, it is possible to preventthe smart diagnosis mode from being entered unnecessarily due to afaulty manipulation of the manipulator 117.

The encoder 142 fetches the product information stored in the memory145, encodes the product information according to a predeterminedencoding scheme and adds a preamble and an error check bit to theresulting data signal, so as to generate a digital signal of apredetermined format. The encoder 142 generates a digital signalconsisting of a plurality of symbols by encoding the productinformation.

The encoder 142 encodes the product information using a bit errorcorrection coding scheme to protect against data loss that may occurduring transmission of the product information as a sound signal overthe communication network. The encoder 142 uses a forward errorcorrection (FEC) scheme as an example of the bit error correction codingscheme. The encoder 142 encodes the product information usingconvolutional coding. Thus, the diagnostic server of the service center200 decodes the sound using a Viterbi decoding algorithm as theconvolutional coding.

The encoder 142 performs such encoding based on a ½ code rate scheme, inwhich 2 bits are output for 1 bit input, or based on a ⅔ code ratescheme. In addition, the encoder 142 reduces the number of redundantbits using a puncturing algorithm.

The encoder 142 also performs bit interleaving against burst errors thatmay occur during data transmission. The encoder 142 performs bitinterleaving on data on the basis of a predetermined number of bits, forexample, 32 bits. That is, when the data is 60 bytes, the encoder 142performs bit interleaving on data by permuting the data on a four byfour byte basis according to a predetermined rule.

In the course of generating the digital signal, the encoder 142 maydivide the digital signal into a plurality of frames by a predeterminedsize and packetize the frames into a packet. Also, the encoder 142 mayset an inter-frame space (IFS) of a predetermined duration betweenadjacent ones of the frames of the digital signal. Also, during signalconversion, the encoder may set a dead time in a symbol in a period inwhich a data value is changed, in order to eliminate reverberation thataffects the next signal conversion due to the principle of charging anddischarging of a capacitor.

Assuming that the length of each of the symbols constituting the digitalsignal is a symbol time and the fundamental length of a frequency signalconstituting the sound signal from the sound output device 160,corresponding to each symbol, is also a symbol time, the encoder 142 mayset a dead time within the symbol time with respect to one symbol. Inthis case, the length of the dead time varies with the length of thesymbol time.

The product information includes operation information includingoperation settings, operating state data, etc., usage information, andfault information about a faulty operation, as stated above. The productinformation is data consisting of a combination of 0s or 1s, which is adigital signal of a format readable by the controller 140.

The controller 140 generates a digital signal of a predetermined formatby classifying data of the product information, incorporating specificdata into the classified data and dividing the resulting data by acertain size or combining the resulting data, and applies the generateddigital signal to the modulator 150.

Also, the controller 140 may change the number of symbols correspondingto output frequency signals according to the number of frequencies usedin the modulator 150.

The modulator 150 applies a drive signal to the sound output device 160in response to the digital signal from the controller 140 such that thesound output device 160 outputs a sound signal. The sound signal outputin this manner includes product information.

The modulator 150 applies the drive signal to the sound output device160 such that a specified frequency signal corresponding to one of thesymbols constituting the digital signal is output for a symbol time.

The modulator 150 performs a control operation such that the soundsignal is output through a plurality of frequency bands in accordancewith the digital signal while changing the number of symbols for eachfrequency signal based on the number of used frequencies in accordancewith setting of the controller 140. For example, one frequency signalmay be output per 1 symbol when two frequencies are used and onefrequency signal may be output per 2 symbols when four frequencies areused.

The modulator 150 includes frequency oscillators (not shown) forgenerating as many oscillation frequencies as the number of availablefrequencies and controls the sound output device 160 to output frequencysignals from frequency oscillators that are specified in accordance withthe digital signal.

The modulator 150 converts the digital signal from the controller 140into the sound signal using one of frequency shift keying, amplitudeshift keying, or phase shift keying while controlling the sound outputdevice 160 to output the sound signal in accordance with the digitalsignal.

Frequency shift keying converts the digital signal into a signal havinga frequency corresponding to a data value of the digital signal,amplitude shift keying converts the digital signal by changing theamplitude of the digital signal according to the data value, and phaseshift keying converts the digital signal by changing the phase of thedigital signal according to the data value.

Binary frequency shift keying (BFSK), which is a type of frequency shiftkeying, converts the digital signal into a signal of a first frequencywhen the digital signal has a data value of 0 and into a signal of asecond frequency when it has a data value of 1. For instance, BFSKconverts data value 0 into a signal of a frequency of 2.6 KHz andconverts data value 1 into a signal of a frequency of 2.8 KHz.

Amplitude shift keying may convert the digital signal into a signal of afrequency of 2.6 KHz with an amplitude of 1 when the digital signal hasa data value of 0 and an amplitude of 2 when it has a data value of 1.

While the modulator 150 has been described as using frequency shiftkeying as an example, the modulation scheme used may be changed. Also,the frequency bands used are a mere example and may be changed.

If a dead time is set in the digital signal, the modulator 150discontinues modulation during an interval in which the dead time is setin the digital signal. The modulator 150 modulates the digital signalusing pulse width modulation (PWM) and switches an oscillation frequencyfor modulation off during the interval, in which the dead time is set,to temporarily discontinue the frequency signal modulation during thedead time. This controls inter-symbol reverberation of the sound signaloutput from the sound output device 160.

The sound output device 160 is activated or deactivated according to acontrol command from the controller 140. The sound output device 160emits a predetermined sound signal including product information byoutputting a frequency signal corresponding to the digital signal for aspecified time under the control of the modulator 160.

Here, one or more sound output devices 160 may be provided. For example,when two sound output devices are provided, one of the two sound outputdevices may output a sound signal including product information and theother may output an alarm sound or an effect sound corresponding tostate information of the home appliance and may also output anindication sound before a smart diagnosis mode is entered or before thesound signal is output.

The sound output device 160 is deactivated after completely outputtingthe digital signal as the predetermined sound signal in accordance withthe output of the modulator 150. When the selector 130 is manipulatedagain, the sound output device 160 is reactivated to output thepredetermined sound signal carrying product information through theabove-described process.

While a sound output unit such as a speaker or a buzzer is applicable asthe sound output device 160, a speaker having a wide reproductionfrequency range is preferable in order to use a plurality of frequencybands.

When the smart diagnosis mode is entered, the sound output device 160emits a start sound indicating the start of the smart diagnosis modeaccording to a control command from the main controller 141 and alsooutputs respective predetermined indication sounds at the start and endof outputting a sound signal carrying product information.

In response to a control command from the main controller 141, thedisplay device 118 displays, on a screen, information such asinformation received from the selector 130 and the manipulator 117,operating state information of the home appliance 101, and informationassociated with completion of the operation of the home appliance 101.When the home appliance 101 operates abnormally, the display device 118also displays fault information about the abnormality on the screen.

The display device 118 displays information indicating the smartdiagnosis mode when the smart diagnosis mode has been started inresponse to a control command from the main controller 141. When thesound output device 160 outputs a sound signal, the display device 118displays the progress of the sound output in the form of at least one oftext, an image, and a numeral.

The home appliance 101 may include an output unit such as anilluminating or flickering lamp, a vibrator, or the like, which will notbe described herein, in addition to the sound output device 160 and thedisplay device 118.

The home appliance 101 constructed as described above outputs thepredetermined sound signal to transmit product information of the homeappliance 101 to the service center 200 as described below.

FIG. 4 is a block diagram of the diagnostic server of the service centerin the home appliance diagnostic system illustrated in FIG. 1.

When the home appliance 101 emits a sound signal, the sound signal isprovided to the portable terminal 80 and then transmitted to the servicecenter 200 over the communication network. The service center 200receives the sound signal and applies it to the diagnostic server, whichthen performs a fault diagnoses of the home appliance 101 based on thesound signal.

Referring to FIG. 4, the diagnostic server of the service center 200includes a communicator 220, a signal processor 230, a data device 240,a server input device 280, a server output device 270, a diagnoser 260,and a server controller 210 for providing overall control to thediagnostic server.

The server input device 280 and the server output device 270 provide apredetermined input/output interface, through which a manager of theservice center 200, a user, and a service technician may check theprogress and result of a diagnosis, and receive or output data.

The server input device 280 includes input units such as buttons, keys,a touchpad or a switch that the user of the service center 200manipulates. The server input device 280 includes a connection interfacefor interfacing with an external input device and a portable memory.

When a specific input unit of the server input device 280 ismanipulated, the server input device 280 applies a signal to the servercontroller 210 to allow the diagnostic server to receive a sound signalfrom the home appliance 101 through the telephone or mobile phone of theuser connected to the diagnostic server over the telephone network ormobile network.

The server output device 270 includes a display for displaying operationinformation and diagnosis results of the diagnostic server.

The communicator 220 is connected to an internal network of the servicecenter 200 and transmits and receives data to and from the network. Thecommunicator 220 is also connected to an external network such as theInternet to communicate with the external network. Especially uponreceipt of a recording command or a reception command through the serverinput device 280, the communicator 220 receives a sound signal from thehome appliance over the telephone network and transmits a diagnosisresult externally when a diagnosis is completed, according to a controlcommand from the server controller 210.

The communicator 220 transmits the diagnosis result to the terminal ofthe service technician or to the portable terminal of the user.

The data device 240 stores control data for controlling the operation ofthe diagnostic server, a sound signal received from the home appliancesuch as a laundry treatment machine in the form of sound signal data,reference data for sound signal conversion and product informationextraction, and fault diagnostic data for diagnosing whether the homeappliance is out of order and the cause of a fault.

Also, the data device 240 stores temporary data generated during theprocess of converting received data or detecting product information andalso stores diagnosis result data and a diagnosis result report to betransmitted to the user.

The data device 240 receives, outputs, manages, and updates data underthe control of the server controller 210.

The signal processor 230 converts the received sound signal into areadable sound signal, extracts product information from the convertedsound signal, and applies the product information to the diagnoser 260.

The signal processor 230 converts and stores the received analog soundsignal. The signal conversion is the reverse of signal conversion in thehome appliance 101. Preferably, each home appliance and the diagnosticserver convert data using the same scheme preset by agreementtherebetween. The signal processor 230 converts an analog sound signalin a predetermined frequency band into a digital signal throughdemodulation using one of frequency shift keying, amplitude shift keyingor phase shift keying.

After extracting the digital signal on a frame basis from thedemodulated data, the signal processor 230 acquires the productinformation by decoding the digital signal. The signal processor 230detects a preamble, acquires the digital signal including the productinformation based on the preamble, and extracts the product informationof the home appliance from the digital signal by decoding the digitalsignal of a predetermined format using a decoding scheme correspondingto the coding scheme used for the product information in the homeappliance.

The signal processor 230 converts and analyzes the digital signal basedon structure or format information, frequency characteristics, anddecoding information of the digital signal stored in the data device240.

The product information is applied to the diagnoser 260 and stored inthe data device 240.

The diagnoser 260 determines the operating state of the home appliance101 and whether the home appliance 101 is out of order by analyzing theinput product information according to a control command from the servercontroller 210. The diagnoser 260 has a diagnosis program for analyzingthe product information of the home appliance and determining the stateof the home appliance based on the product information, and diagnosesthe home appliance 101 using the fault diagnostic data stored in thedata device 240.

Also, the diagnoser 260 analyses the cause of the fault, derives asolution or a measure to take against the fault, and outputs a diagnosisresult in relation to a customer service direction.

The diagnoser 260 classifies data of the product information accordingto a predetermined criterion and performs the fault diagnosis accordingto a combination of associated data among the classified data. Duringthe fault diagnosis, the diagnoser 260 determines which item iscorrectly diagnosable and which item is not correctly diagnosable andperforms fault diagnosis on diagnosable items in descending order offault probability.

The diagnosis result includes a fault ID or location, aprobability-based fault cause list, a defective part list, and guidanceinformation indicating whether a service technician is to be dispatched.

The server controller 210 controls data transmission and receptionthrough the communicator 220 and data input and output through theserver input device 280 and the server output device 270. In addition,the server controller 210 controls the operations of the signalprocessor 230 and the diagnoser 260 to diagnose the fault of the homeappliance 101. The server controller 210 performs a control operationsuch that the diagnosis result of the diagnoser 260 is output throughthe server output device 270 and transmitted through the communicator220.

The server controller 210 performs a control operation such that thediagnosis result of the diagnoser 260 is output through the serveroutput device 270. Hence, the service center 200 notifies the user of anaction to be taken in relation to the malfunction of the home appliance101 by voice over the telephone network or dispatches a servicetechnician to the user. In the latter case, the server controller 210transmits the diagnosis result to the terminal of the service technicianthrough the communicator 220.

Also, the server controller 210 may transmit the diagnosis result to theuser through the communicator 220.

In the mean time, when an error has occurred during the signalprocessing or the diagnosis process, the server controller 210 outputsan alarm sound or a message requesting sound signal retransmission ofthe home appliance 101 through the server output device 270. In thiscase, the service center 200 requests the user connected thereto throughthe communication network to re-output a sound signal of the homeappliance.

The product information of the home appliance, which is transmittedafter being converted into a sound signal for fault diagnosis, includesa plurality of data associated with the operations of the homeappliance. The home appliance stores a plurality of diagnostic datarequired for fault diagnosis. The following describes the productinformation.

As described above, the home appliance stores product information in thememory 145 and the product information includes a plurality ofdiagnostic data.

The main controller 141 stores diagnostic data corresponding to theoperating state of the home appliance in the memory 145 or stores thediagnostic data in the memory 145 after temporarily storing it in thestorage device 146. Here, the main controller 141 changes the time orfrequency of storage of the diagnostic data according to the type of thediagnostic data.

The main controller 141 reads the diagnostic data stored in this mannerwhen the smart diagnosis mode is entered, encodes the read diagnosticdata into a digital signal in a predetermined format through the encoder142, converts the digital signal into a sound signal through themodulator 150, and outputs the sound signal through the sound outputdevice 160.

The main controller 141 performs data initialization before startingoperation and stores diagnostic data at intervals of a specific periodor as needed while the main controller 141 operates according tosetting. Here, the main controller 141 maintains initial values of anoperation that has not been actually performed although it has been setto be activated.

Depending on the type of the diagnostic data, the main controller 141stores diagnostic data immediately each time the data value of thediagnostic data has changed, stores diagnostic data when an error hasoccurred, or stores diagnostic data associated with each operation suchas washing, rinsing, or spin-drying upon completion of the operation.

Thus, the memory 145 stores product information including the operationinformation, the usage information and the fault information undercontrol of the main controller 141. The storage device 146 also storestemporary data about the operation information and fault informationgenerated during the operation of the home appliance. For example, theproduct information may include the number of uses of the laundrytreatment machine, a set course, option setting information, an errorcode, a value measured by a sensor, data calculated by the controller140, and operation information of each component.

In the case of the laundry treatment machine, the operation informationincludes information necessary for the operation of the laundrytreatment machine, such as information about the washing mode of thelaundry treatment machine, information about the spin-drying mode of thelaundry treatment machine and information about the rinsing mode of thelaundry treatment machine.

The fault information may include, when the laundry treatment machineperforms each operation, various information including fault informationgenerated during each operation, device fault information of the laundrytreatment machine, error codes corresponding to fault information,information of the controller 140, values sensed by the sensing device170, sensed values of the motor, fault information of the wash watersupply, and fault information of the drainage device.

The usage information may include various information including thenumber of uses of the laundry treatment machine by the user, a courseset by the user, and option setting information set in the laundrytreatment machine. That is, the usage information may include contentsinput to the laundry treatment machine by the user or informationinitially set in the laundry treatment machine.

The product information is stored as in the following table.

TABLE 1 Category Name Size (byte) Operation info Status 1 Customer infoCommon 11 Wash 4 Rinse 4 Spin 6 Dry 8 Error code 1 Counts 8 Options 9

Referring to Table 1, “Category” indicates the attributes of the productinformation and “Name” provides the meaning of each category.

“Status” indicates information of a mode which is performed last amongall modes of the laundry treatment machine 101. That is, “Status”indicates product information of the laundry treatment machine 101 aboutthe rinsing mode when the laundry treatment machine 101 performs therinsing mode last among the washing, spin-drying, and rinsing modes atthe request of the user. “Status” is 1 byte long.

“Common” is product information having an attribute that should besampled over all modes of the laundry treatment machine 101. That is,“Common” indicates product information in each mode or at a specifictime when the motor, the wash water supply, and the like operatethroughout all modes of the laundry treatment machine 101. “Common” isset to be 11 bytes long. Here, data having a “Common” attribute isinitialized at a preparatory step before the operation starts and isstored as needed during the operation and is also stored when a failurehas occurred or when the operation is terminated. Depending on the typeof the “Common” data, the “Common” data may be stored only when aspecific error has occurred.

“Wash” indicates product information having an attribute that should besampled in the washing mode. For example, “Wash” provides productinformation having an attribute that should be sampled in the washingmode such as the level of wash water or the operation time of the washwater supply when the washing mode is performed. “Wash” is set to be 4bytes long. Data about “Wash” is stored when the washing mode is beingperformed or when the washing mode has been completed and is also storedwhen an error has occurred. Here, when spinning, which is the lastoperation of the washing mode, has been completed, it is determined thatthe washing mode has been completed, and diagnostic data about “Wash” isstored before rinsing starts, i.e., before water supply starts in therinsing mode.

“Rinse” indicates product information having an attribute that should besampled in the rinsing mode. “Rinse” is 4 bytes long. “Spin” indicatesproduct information having an attribute that should be sampled in thespin-drying mode. Data about rinsing is stored while the rinsing mode isperformed, when the rinsing mode is completed, or when an error hasoccurred. Rinsing data is stored during each rinsing operation anddiagnostic data about rinsing is finally stored before the spin-dryingmode starts after spinning is performed in the last rinsing operation.

Here, “Spin” is set to be 6 bytes long. “Dry” indicates productinformation having an attribute that should be sampled in the dryingmode. “Dry” is set to be 8 bytes long. Diagnostic data about spin-dryingis stored when the spin-drying mode has been completed or when an errorhas occurred.

In the washing, rinsing, and spin-drying mode, diagnostic data aboutbubble detection is stored immediately upon bubble detection.

“Error code” indicates a code of an error, of which the user is alertedupon detection of an abnormality in the laundry treatment machine 101while in operation. That is, “Error code” indicates a typical operationerror of the laundry treatment machine 101, of which the user is alertedwhen an abnormality has occurred in the laundry treatment machine 101.“Error code” is set to be 1 byte long.

For example, “Error code” indicates an error message displayed on adisplay (not shown) or a beep emitted through a buzzer when the laundrytreatment machine 101 has malfunctioned or a usage error has occurred.Among product information, such an error code is set to inform the userof the location of an error in the laundry treatment machine 101 whichhas malfunctioned. The error code may not only be displayed on thedisplay device but may also be output as an alarm sound.

For example, when an error code included in product information has adata value of 0, the error code indicates that the laundry treatmentmachine 101 is functioning normally or indicates that a malfunction,which is not classified as an error code, has occurred in the laundrytreatment machine 101. An error code having a data value of “1” mayindicate a door malfunction, “2” a water supply malfunction, “3” adrainage malfunction, “4” a balance malfunction, “5” an FE malfunction,“6” a switch sensor (PE) malfunction, “7” a water supply (IE)malfunction, “8” a motor (LE) malfunction, “9” a CE malfunction, and“10” a drying malfunction. Error codes having other data values mayindicate other specific malfunctions.

Such an error code is used to extract associated data according to thevalue of the error code when the diagnostic server has diagnosed thelaundry treatment machine 101 with a fault, to compare the extracteddata with corresponding reference data or diagnostic data to analyze thecause of the fault, and to derive a measure to take against the fault.The diagnostic server determines an operation of the laundry treatmentmachine 101 during which the fault has occurred based on stateinformation included in the product information.

“Counts” indicates product information specifying the number of uses ofthe laundry treatment machine 101 by the user, the number of erroroccurrences, etc. “Counts” is set to be 8 bytes long. When the laundrytreatment machine 101 has started operation, “Counts” is notinitialized, maintaining its previous value, at a preparatory step.

“Options” indicates product information including options that the userhas set when operating the laundry treatment machine 101. That is, theuser sets “Options” for the laundry treatment machine 101, for example,a washing time to 15 minutes, a spin-drying time to 5 minutes, and arinsing time to 10 minutes as “Options”. “Options” is set to be 9 byteslong. “Options” are stored when an error code has occurred or when thewashing mode has been completed.

The sizes, categories, and names of product information are merely anexample and thus may be changed depending on the characteristics of thehome appliance.

The main controller 141 causes the home appliance to operate accordingto setting values such as options or an operation course set through themanipulator 117 of the input device 125. For example, when the homeappliance is a laundry treatment machine, the main controller 141classifies its operation steps into preliminary, washing, rinsing,spin-drying, drying, and termination steps and further classifies eachstep into operations and stores information indicating an operation thatthe home appliance has performed last as state information.

Thus, the state information includes information about the operationthat the home appliance has performed last among all operations of thehome appliance. For example, the state information includes informationabout an operation step that the home appliance performs last amongpreliminary, washing, rinsing, spin-drying, drying, and terminationsteps into which operation steps of the laundry treatment machine aredivided before the laundry treatment machine performs specifiedoperations. Here, each step may be classified into sub-steps. Forexample, the washing step may be further classified into rough washing,soaked washing, main washing, and finishing washing steps and therinsing step may be further classified into first-time rinsing,second-time rinsing, third-time rinsing, and fourth-time rinsing steps.The first-time rinsing step may also be further classified into adrainage step, a brief spinning step, a main spinning step, and a watersupply step. The state information includes information about suchfinely classified operations of the home appliance.

When an abnormality has occurred during the rinsing mode of the laundrytreatment machine, a value indicating the rinsing mode is stored in thestate information since the rinsing mode has been performed last. Here,each mode may be further classified and thus the state information mayindicate in which rinsing step the abnormality has occurred in therinsing mode, whether the abnormality has occurred during the spinningstep in the rinsing mode, whether the abnormality has occurred duringwater supply, and whether the abnormality has occurred during drainage.

Here, the state information may be about 1 byte long and may includeinformation about each of about 60 to 64 operations into which the stepsof the home appliance are divided.

Here, the values “0” to “5” of state information may indicate operationsof a preliminary step, specifically, the value “0” may indicate aninitialization step, “2” a stop step, “3” a course scheduling step, “4”a freezing detection step, and “5” a laundry quantity detection step.The values “55” and “56” may indicate drying steps, specifically, thevalue “55” may indicate a hot air drying step and “56” a cool-down step.

The values “6” to “9” may indicate the rough washing mode, “10” and “11”the soak mode, “12” to 20” the wash mode, “21” to “48” the rinsingmode”, “49” to “52” the spin-drying mode, “55” and “56” the drying mode,and “57” to “59” the termination mode. When the data value of the stateinformation is “0”, this indicates that power is off and, when the datavalue is “12”, this indicates that initial water supply has beenperformed last in the washing mode. When the value of the stateinformation is “28”, this indicates that brief spinning has beenperformed last in the second-time rinsing step.

This state information is updated as needed during operation of the homeappliance. That is, while the washing mode is being performed,corresponding state information is stored and, when the rinsing mode isperformed after the washing mode is completed, a corresponding value isstored as state information.

The diagnostic server can determine which operation has been performedlast in the home appliance through the state information included in theproduct information and perform fault diagnosis using associateddiagnostic data.

Common data described above is stored in the storage device 146immediately each time data is created or each time the value of data haschanged. Common data is temporarily stored in the storage device 146 andis then stored in the memory 145 when the home appliance has stoppedoperation since all operations are completed or since an error hasoccurred.

“Current Limit Counter” indicates the total number of current limitoperations until the home appliance terminates operation after startingoperation. The current limit counter is incremented by 1 each on-offcycle of the motor.

When the motor controller generates and applies a signal for controllingthe motor to the motor, an excessive current exceeding an allowablelevel may be generated, damaging the motor controller and the motor.Thus, the motor controller performs a “current limit” operation toforcibly cut off a motor current when the level of the current hasreached a limit level which is preset to prevent damage to the motorcontroller and the motor due to overcurrent.

“FO Counter,” which is an overcurrent control counter, indicates thetotal number of times overcurrent is cut off by hardware until the homeappliance terminates operation after starting operation. The FO limitcounter indicates the number of times overcurrent is limited by hardwareand is maintained at “0” when the motor controller performs normalcontrol. Thus, when the value of the FO counter is zero, this indicatesthat the motor controller is functioning normally and, when the value ofthe FO counter is nonzero, this indicates that an error has occurred inthe motor controller, i.e., that the motor controller is out of order.

“Bubble_Counter” indicates the total number of times bubble detection isperformed until the home appliance terminates operation after startingoperation.

“RPM Detect” indicates a rotation speed value of the motor that a hallsensor provided for the motor has measured during operation of themotor. The RPM Detect data enables determination of abnormality in themotor or hall sensor. For example, when the current limit counter isnonzero while the “RPM Detect” value is zero indicating that no rotationspeed has been measured, it can be determined that the hall sensor hasfailed to measure the rotation speed since the hall sensor is out oforder although the motor has been activated.

Here, an “RPM Detect” value of “0” indicates that the hall sensor andthe motor are normal, “1” indicates that the RPM is 0, and “2” indicatesthat the RPM is kept at 0 for the last two seconds or that the RPM wasnonzero at least once for the remaining time.

The “RPM Detect” value is stored each time it is detected and thus an“RPM Detect” value stored last is maintained as a final motor speedmeasurement.

“Power off info” includes information as to whether the home appliancehas terminated operation when power is turned off after completing allset operations or without performing part of the set operations. Forexample, the value of “Power off info” may be 1 when power is turned offdue to power failure.

“Water Level End” includes water level measurement of the tub when thehome appliance has terminated operation.

“Error Water Drainage Time” indicates the time required for drainage(drainage time) and, specifically, a drainage time that was stored lastis stored in this information upon occurrence of an error. The “ErrorWater Drainage Time” value is changed when drainage is performed and thelarger of a previously stored value and a newly measured value is storedas the “Error Water Drainage Time” value. Thus, the maximum timerequired for drainage is stored as the error water drainage timeinformation. That is, the longest of the drainage times measured whendrainage was performed a number of times is stored as the “Error WaterDrainage Time” value.

Namely, the “Error Water Drainage Time” value indicates the longest ofall operation times required for drainage which are measured duringdrainage operations and thus a measured drainage time value is storedwhen it is greater than a previously stored value such that the maximumdrainage time is stored as the “Error Water Drainage Time” value.

“IPM Max Temperature” indicates a measured temperature of the motorcontroller that applies a control signal to the motor. While the motorcontroller generates and applies a motor control signal to the motor,the motor controller generates heat since it performs a large amount ofcalculation. The temperature of the motor controller is measured andrecorded since the motor controller may be damaged when the temperaturehas exceeded a certain level.

“Error Temperature” includes information about a temperature sensor,which has measured an abnormal temperature or a temperature error, amonga plurality of temperature sensors provided in the home appliance. Forexample, an error temperature value of “0” indicates that there is noabnormality, “1” indicates a temperature sensor provided on the tub, “2”indicates a temperature sensor provided on an AF, and “3” indicates atemperature sensor provided on a duct. Here, the order or types oftemperature sensors corresponding to the error temperature values may bechanged according to setting.

That is, the error temperature value “1” indicates that an abnormaltemperature is measured at the temperature sensor provided on the tub.

Here, each temperature sensor provided on the home appliance appliesdata corresponding to a measured temperature to the main controller. Thevalue input to the main controller is not the measured temperature levelbut instead is a corresponding one of 255 levels into which resistance,current, or voltage values corresponding to temperature are classified.

When a value measured by a temperature sensor is 0 or 255, the maincontroller may determine that the temperature sensor is out of ordersince the values 0 and 255 cannot be measured when the temperaturesensor operates normally and are measured due to a wiring or connectionproblem. The value 0 or 255 may also be applied to the main controllerwhen temperature exceeds a range of temperature levels that can bemeasured by the temperature sensor. In the case of the laundry treatmentmachine, such abnormal data is applied to the main controller whentemperature of a dryer heater exceeds the measureable range of atemperature sensor provided on the dryer heater due to overheatingcaused by failure of the fan. Thus, the main controller storesinformation of the temperature sensor as the error temperatureinformation.

“Error Bubble Flag” indicates whether bubbles have been detected uponerror occurrence and is set when bubbles have been detected and iscleared when bubbles have been removed.

“Error Voltage” indicates a voltage value measured upon erroroccurrence. A generally measured voltage value is not stored as the“Error Voltage” value. Instead, the measured voltage value is convertedinto one of a plurality of levels into which measured voltage values areclassified and the converted level is stored as the “Error Voltage”value.

“Fan motor RPM” indicates a rotation speed of the fan motor when anerror code has occurred. The rotation speed of the fan motor ismeasured, before the fan motor is deactivated, and the fan motor isdeactivated after the measured rotation speed is stored as the “Fanmotor RPM” value.

Specifically, when the cool-down step is entered, the rotation speed ofthe drying fan in the laundry treatment machine is measured and storedas the “Fan motor RPM”.

“ReWater Flag” is set during water resupply and is cleared when waterresupply is completed. The “ReWater Flag” value is stored when an errorhas occurred or when the operation is terminated. The “ReWater Flag”value is set depending only on whether water resupply is beingperformed, regardless of whether water resupply is performed in thewashing step or in the rinsing step.

“Door Bimetal Flag” stores an on/off state of a bimetal on the door whena door-related error has occurred.

Data used in the overall operation of the laundry treatment machine asdescribed above is temporarily stored and updated as needed and isstored in the memory when an error has occurred or when the operation isterminated.

The diagnostic data includes data items corresponding to operationswhich are stored according to operating states.

In the operation steps of the washing mode, a wash water supply time, awash water temperature, a wash bubble flag, a wash low-voltage flag, awash valve switching flag, and a heater forcible cut-off flag are storedas diagnostic data of the washing mode. These data items are temporarilystored and updated during the washing mode and are stored in the memorywhen washing is completed.

Here, the wash water supply time data “Water supply time_W” is the timerequired for water supply in the initial water supply step, i.e., thetime required until water supply is completed after water supply starts.The stored wash water temperature data includes a first wash watertemperature “Water Temperature W0” and a second wash water temperature“Water Temperature W1”. Here, a temperature of the tub when theoperation starts is stored as the first wash water temperature and atemperature of the tub immediately after the initial water supply iscompleted is stored as the second wash water temperature. That is, thefirst wash water temperature “Water Temperature W0” is a temperature ofthe tub that is measured when the operation starts, i.e., when watersupply starts. The first wash water temperature is not measured whenwater supply is resumed after being stopped. On the other hand, thesecond wash water temperature “Water Temperature W1” is a temperature ofthe tub that is measured immediately after the initial water supply iscompleted. The temperature of the tub can be considered the temperatureof the wash water since the temperature of the tub varies with thetemperature of the wash water when water supply is performed. Whetherthe state of water supply, the sensor, or the like are out of order isdetermined by comparing the two wash water temperatures.

The wash bubble flag indicates whether or not bubbles have occurredduring washing and spinning in the washing mode and may be set to “1”when bubbles have occurred and set to “0” when no bubbles have occurred.The wash low-voltage flag is set when a low voltage has been input. Thewash valve switching flag is a flag associated with erroneous connectionof cold and hot water valves. The heater forcible cut-off flag is set toa value indicating whether the heater has been forcibly cut off based onthe heating time. Specifically, the heater forcible cut-off is stored asa history of forcible cut-off of the heater due to an excessive heatingtime and forcible cut-off of the heater due to no temperature change.When the heater has been cut off at least once, the heater forciblecut-off flag is set to “1”, indicating that forcible heater cut-off hasoccurred.

Diagnostic data of the rinsing mode includes a rinse water supply time,a rinse water temperature, a rinse bubble flag, a rinse low-voltageflag, and main rinse valve information and are temporarily stored andupdated while the rinsing mode is being performed or when the rinsingmode is completed and are finally stored in the memory when the rinsingmode is completed.

The time required for water supply for rinsing is stored as the rinsewater supply time as in the washing mode. When rinsing is performed aplurality of times, the maximum of a plurality of measured rinse watersupply times is stored as the rinse water supply time. The rinse watertemperature data includes a first rinse water temperature and a secondrinse water temperature, which are tub temperatures measuredrespectively before and after water supply, as in the washing mode. Thetemperature difference between before and after water supply can bedetermined using the first and second rinse water temperatures.

The rinse bubble flag is set or cleared according to whether bubbleshave occurred during rinsing. The rinsing low-voltage flag is set when alow voltage is generated during rinsing or spinning in the rinsing mode.The main rinse valve information includes information indicating whetherthe main valve used for final rinsing is a cold water valve or a hotwater valve.

Diagnostic data of the spin-drying mode includes a spin-dry entry trialcount “UB try counter”, a wet load level, an offset value, a targetrotation speed, a maximum rotation speed, a spin-dry bubble flag, and aspin-dry low-voltage flag and are stored while the spin-drying mode isbeing performed or when the spin-drying mode is completed.

First, the “UB try counter” value is described as follows. The tub ordrum may bump against the casing of the laundry treatment machine whenspin-drying is performed depending on how much the tub is tilted due tolaundry. Large eccentricity of laundry may cause loud noise and makeshigh-speed spin-drying impossible and may also damage the laundrytreatment machine. Accordingly, the degree of balance or unbalance (oreccentricity) is measured before spin-drying is performed. When thedegree of unbalance or eccentricity is great, the laundry treatmentmachine does not directly start spin-drying and performs an operationfor untangling and uniformly redistributing laundry. That is, the “UBtry counter” data indicates the number of times the laundry treatmentmachine has reattempted entry to the spin-drying step since it cannotperform the spin-drying operation due to large eccentricity. This isproportional to the number of times the laundry treatment machine hasperformed eccentricity measurement and laundry untangling.

The “Wet load level” data indicates the quantity of laundry measuredlast before high-speed spin-drying is performed. Since the laundryquantity measured when washing starts is the quantity of dry laundry,the quantity of wet laundry before spin-drying is performed isrecalculated and stored as the “wet load level” data.

The quantity of laundry may be classified into a plurality of levelssuch as very small, small, middle, normal, large, very large, and singleload levels. The “offset value” is a value for setting a target rotationspeed during spin-drying and the target rotation speed is reset based onthe eccentricity (or the degree of unbalance), regardless of aninitially input operation setting. The maximum rotation speed is a valuemeasured when final spin-drying is performed.

The spin-dry bubble flag is associated with whether bubbles haveoccurred during spin-drying and the spin-dry low-voltage flag indicateswhether a low voltage is generated during spin-drying.

Diagnostic data of the drying mode includes a lowest water level, adryer heater operation count, a lowest dry temperature, a motor rotationspeed, a lowest voltage, a dry time, a maximum fan motor rotation speed(RPM) flag, and a dry low-voltage flag and are stored while the dryingmode is being performed or when the drying mode is completed.

The lowest water level is the lowest of water levels measured until thedrying mode is completed from when initial drainage is completed afterthe drying mode is entered. The dryer heater operation count is thenumber of on and off operations of the dryer heater and the lowest drytemperature is the lowest of duct temperature values measuredimmediately until the cool-down step is entered.

The fan motor rotation speed “fan motor RPM” is a measured rotationspeed value of the dry fan of the laundry treatment machine when thecool-down step is entered. The lowest dry voltage is the lowest ofvoltage values measured during the drying mode after the drying mode isentered. The dry time is a time measured after preliminary drying in thespin-drying mode. The maximum fan motor rotation speed flag is set whenthe rotation speed measured during operation of the fan motor hasexceeded a predetermined speed and the dry low-voltage flag is set whena low voltage is provided in the drying mode.

The diagnoser 260 diagnoses a fault using such data included in theproduct information and derives a solution to the fault.

Not only data according to operations of the home appliance but alsoboth an error occurrence count in the home appliance and setting datainput through the manipulator 117 are included as diagnostic data in theproduct information.

The error occurrence count includes the number of occurrences of errorsof each error code, the number of operations of the home appliance, thenumber of tub washing operations of the laundry treatment machine, orthe like. The setting data includes setting values associated with awash course, a rinsing operation count, a language for use, use ofsteam, sound volume control, spin-drying strength, and wash watertemperature.

The main controller 141 stores such diagnostic data as productinformation in the memory. When the home appliance enters the smartdiagnosis mode in response to input by the user, the main controller 141reads the stored diagnostic data and creates product information and theencoder 142 encodes the product information to generate a digital signalin a predetermined format. The generated digital signal is applied tothe modulator, which converts the digital signal into a combination ofpredetermined frequency signals. The sound output device 160 outputs thecombination of predetermined frequency signals as a predetermined soundsignal.

FIGS. 5 and 6 illustrate a structure of the digital signal and a methodfor encoding the digital signal.

Referring to FIG. 5, the encoder 142 adds a product ID and versioninformation to the product information including the plurality ofdiagnostic data stored as described above and divides the resultingproduct information on a predetermined unit basis to create frames. Theencoder 142 employs a frame check sequence (FCS) for error checking on aframe basis.

For example, when 60-byte data including the product information isdivided by 15 bytes, the 60-byte data is converted into a packetincluding four frames, each 15 bytes long. Here, the number of frames,into which the 60-byte data is divided, i.e., the number of framesconstituting the packet, may vary with the number of bytes by which thedata is divided. The size of each frame changes depending on a symboltime, product information, and an IFS which will be described later.

Referring to FIG. 6, the encoder 142 constructs each frame with a headerand payload.

The frame header includes Frame Type, Reserved, Length, and FCS fields.The payload is a field including a corresponding one of the segmentsproduced through division of the data of the product information, towhich the product ID and the version information are added.

The header is allocated 2 bytes in total, one byte for the Frame Type,Reserved and Length fields and the other for the FCS field, and thepayload is allocated 1 to 15 bytes. Specifically, the Frame Type fieldis 2 bits long, the Reserved field is 2 bits long, and the Length fieldis 4 bits long.

The Frame Type field, which indicates the format and sequence of theframe, resides at bits 6 and 7 in the header except for the FCS field.For instance, if the Frame Type field is set to “00”, this indicatesthat the frame is at the start of the packet. If the Frame Type field isset to “01”, this indicates that the frame is in the middle of thepacket. If the Frame Type field is set to “11”, this indicates that theframe is at the end of the packet.

Thus, the service center 200 identifies the sequence of each frame basedon the Frame Type field of the frame when collecting a plurality offrames.

The Length field represents the length of the payload in the frame asthe number of bytes. Since the length of the payload is 1 to 15 bytes,the Length field has 3 bits expressing the length of the payload at bitpositions 0, 1 and 2 in the header except for the FCS field.

For example, when the Length field is 001, this indicates that thepayload is 1 byte long. When the Length field is 101, this indicatesthat the payload is 5 bytes long.

The FCS field is used to detect whether an error is present in theframe. A Cyclic Redundancy Check-8 (CRC-8) scheme may be used to detectwhether an error is present in the frame.

Necessary information may be inserted in the Reserved field at a designstage. The Reserved field is positioned at bits 4 and 5 in the headerexcept for the FCS field.

The payload is a divided segment of the data illustrated in FIG. 5( a)as described above. In the case where a 60-byte packet is divided intofour frames each having 15 bytes, each frame includes a 15-byte payloadand a frame header is added to the payload, thus completing a finalframe.

The encoder 142 performs FEC encoding on the frames for bit errorcorrection as stated above with reference to FIG. 8. The encoder 142then carries out convolutional coding, puncturing, and interleaving.

Each frame is encoded into an FEC code in the above manner since thesound signal output from the audio output device 160 may be damaged bybackground noise or interference during transmission over thecommunication network

Referring to FIG. 6( c), the encoder 142 encodes the header and payloadof each frame at different code rates. Specifically, the encoder 412encodes and interleaves the 2-byte header at a code rate ½ and the 1 to15-byte payload at a code rate ⅔. That is, the encoder 142 encodes theheader to output a 2-bit symbol for each 1-bit input and encodes thepayload to output a 3-bit symbol for each 2-bit input. Then, the encoder142 reduces the extended length of the frame through puncturing usingthe puncturing matrix described above. The encoder 142 then performs bitinterleaving on the punctured data on a 32-bit basis to protect againstburst errors during transmission.

Here, FEC encoding produces redundant tail symbols. Specifically, tworedundant tail symbols are created due to respective encoding of theheader and the payload. Stuffing bits are added to the encoded result toadjust the number of bits of the encoded result to a fixed number ofbits although the tail symbols may be eliminated through puncturing orinterleaving.

Also, the encoder 142 adds a preamble to the encoded header and payloadin each frame and inserts an IFS between frames.

The preamble indicates the start of the frame and may be formed invarious patterns. For instance, the preamble may be formed in a patternof 0×0FFO.

The IFS is a time period between frames during which no signal isoutput.

The encoder 142 encodes and divides the product information into framesin the above manner to generate a digital signal including the frames,each having a plurality of symbols.

Each frame includes a header, a payload, a preamble, and an IFS, eachincluding a predetermined number of symbols, and thus has a fixed size.Specifically, each frame includes 16 preamble symbols, 32 headersymbols, four header tail symbols, 12 to 180 payload symbols, fourpayload tail symbols, and 16 IFS symbols. The length of stuffing bits,which are added to the encoded or modulated result, varies according tothe length of the encoded or modulated result to adjust the number ofbits to a fixed number of bits. That is, 1 stuffing bit is added to theencoded result when the encoded result is 31 bits long in the case of32-bit alignment.

A packet is divided into a plurality of frames, each including apreamble, a payload, and an IFS inserted between frames, as describedabove. Thus, one frame may include 82 to 252 symbols from the preambleto the IFS and may further include stuffing symbols.

The encoder 142 generates a digital signal for outputting a sound signalby encoding product information into frames and adding preambles andIFSs to the frames as described above. The modulator 150 may modulatethe encoded digital signal including a plurality of symbols on a framebasis. Specifically, the modulator 150 receives and modulates theencoded digital signal into frequency signals and provides the frequencysignals to the audio output device 160. Then the audio output device 160outputs the sound signal including the product information.

FIG. 7 is a waveform diagram illustrating frequency conversion of themodulator.

As described above, a digital signal encoded according to apredetermined scheme through the encoder 142 is frequency-convertedthrough the modulator 150 and then output as a sound signal through thesound output device 160.

For example, the modulator 150 may employ frequency shift keying and usetwo frequencies, 2.6 KHz and 2.8 KHz. In this case, the modulator 150outputs the frequency of 2.6 KHz for a logic value of 0 and thefrequency of 2.8 KHz for a logic value of 1. The frequency of the outputsound signal may vary according to the available frequency band of thesound output device 160. Of course, when the reproduction frequency bandof the sound output device 160 is higher or lower than 2.6 KHz or 2.8KHz, the frequency of each pulse of the sound signal may also beincreased or decreased accordingly.

In the case where the digital signal is 010, the modulator 150 convertsa first bit value 11 of the digital signal into a frequency signal 21 of2.6 KHz because the first bit value 11 is 0, and a second bit value 12of the digital signal into a frequency signal 22 of 2.8 KHz because thesecond bit value 12 is 1. Also, the modulator 150 converts a third bitvalue 13 of the digital signal into a frequency signal 23 of 2.6 KHzbecause the third bit value 13 is 0.

Here, each bit of the digital signal corresponds to one symbol and thelength of a symbol corresponds to a symbol time. When a sound signalhaving one frequency signal corresponding to one symbol is output, thesymbol time may correspond to the length of a basic unit of thefrequency signal of the output sound signal.

When the home appliance 101 transmits a sound signal over a telephonenetwork or a mobile communication network, the data transfer rate of thesound varies with a symbol time. If the symbol time is 30 ms, about 30seconds are required to transmit 100 bytes of data.

The symbol time or size should be reduced to increase the data transferrate. Reducing the symbol time indicates decreasing the number of pulsesof each frequency signal output according to a symbol.

Here, for ease of explanation, let us assume that the basic unit of thefrequency signal of the output sound signal is a symbol. When eachsymbol is modulated and reproduced in an audible frequency band, thedecreased number of pulses per symbol also decreases a reproduction timeof the symbol, which may cause the sound output device 160 to output anincorrect sound signal. The output sound signal may further undergosignal attenuation or distortion during transmission over the telephonenetwork or the mobile communication network. Hence, the service center200 may fail to diagnose the home appliance 101 using the sound signalor misdiagnosis may occur.

Thus, the number of pulses of one symbol, i.e., the number of pulsesincluded in one frequency signal output according to one symbol, isdetermined appropriately and the symbol time is set according to thedetermined number of pulses, thereby not only reducing the size of dataof the sound signal and the transfer rate of the data but also enablingcorrect sound signal output and transmission.

The symbol size, i.e., the symbol time, is set not only taking intoaccount the total length of a digital signal to be output as a soundsignal, the total length of the sound signal to be output, and the datarate of the sound signal but also taking into account whether the soundsignal can actually be output as a desired sound and whether the soundsignal can be transmitted over the communication network. A dead timeand an IFS may be determined according to the symbol time set in thismanner.

The period of each pulse in a symbol is determined according to thereproduction frequency bands of the audio output device 160, forexample, according to 2.6 KHz and 2.8 KHz. Thus, the number of pulses inthe same time interval is equal for the same frequency. Since a mobilephone performs sampling on a sound signal in an audible frequency bandafter receiving the sound signal, the size of each symbol should not bereduced below a certain value.

Hence, the number of pulses per symbol is determined to be at least 8and the symbol time is determined to be 3 ms or longer. The number ofpulses included in one frequency signal corresponding to one symbol maybe set within a range of 8 to 67. When one symbol includes 8 to 32pulses, the home appliance 101 can transmit data using a sound signal tothe portable terminal 80 with almost no errors at a maximum data rate.If the symbol time is shorter than 7 ms, the portable terminal 80 mayfail to correctly acquire a reproduced sound from the audio outputdevice 160, causing a recognition error. If the symbol time exceeds 24ms, the data rate of the sound signal transmitted from the homeappliance 101 to the portable terminal 80 is reduced.

FIG. 8 is a flow chart illustrating a diagnostic method for a homeappliance diagnostic system according to the present invention.

As shown in FIG. 8, when the home appliance 101 outputs productinformation as a predetermined sound signal, the sound signal istransmitted to the service center 200 over a communication networkthrough which the user is connected to the service center 200.

The diagnostic server of the service center 200 receives the soundsignal output from the home appliance 101 (310) and converts the soundsignal according to a predetermined scheme to extract the productinformation (S320). The diagnostic server then diagnoses the state,fault, and fault cause of the home appliance using a plurality of dataincluded in the product information and starts fault diagnosis todetermine a measure to take against the fault (S330).

The diagnoser 260 then obtains version information of the home appliancediagnostic system and model information of the home appliance throughthe plurality of data included in the product information and analyzesdiagnostic data included in the product information to perform faultdiagnosis.

The diagnoser 260 first analyzes state information or an error codeincluded in the diagnostic data included in the product information andcompares data associated with the state information or error code withfault diagnostic data or reference data to perform fault diagnosis.Basically, the diagnoser 260 can use all diagnostic data included in theproduct information. However, the diagnoser 260 can use stateinformation or an error code included in the diagnostic data to analyzedata associated with the state information or error code, therebychecking the state of the home appliance and performing fault diagnosismore quickly. Here, the diagnoser 260 classifies diagnostic dataincluded in the product information according to a predeterminedcriterion, i.e., according to the state information or error code, tofind and diagnose a fault that is the most likely cause of abnormalityof the home appliance.

The diagnoser 260 checks whether an error code has been set in theplurality of diagnostic data included in the product information (S340).When the error code is zero or an unregistered error code has beengenerated, the diagnoser 260 determines that no error code has beengenerated and performs fault diagnosis on the home appliance usingdiagnostic data or state information, other than the error code,included in the product information (S350).

When an error code has been set, the diagnoser 260 determines that theerror code has been generated in the home appliance, identifies aportion of the home appliance, in which abnormality has occurred, usingthe error code, extracts diagnostic data associated with the identifiedportion, and performs fault diagnosis using the extracted diagnosticdata (S360).

The diagnoser 260 diagnoses the cause of the fault and derives a measurefor or a solution to the fault cause (S370). The diagnoser 260 storesthe fault cause and the solution derived through such fault diagnosis asa diagnosis result (S380).

Since the home appliance may have a plurality of faults, the diagnoser260 performs additional diagnosis using other associated diagnostic datacorresponding to the type of the error code (S390, S360, and S380).

When diagnosis is completed, the diagnoser 260 applies the diagnosisresult to the server controller 210.

The server controller 210 generates a final diagnosis result through thediagnosis result received from the diagnoser 260 (S400). That is, whenthe home appliance has a plurality of faults, there may be a number ofcauses of and solutions to the faults, and therefore the servercontroller 210 combines at least one diagnosis result received from thediagnoser 260 to generate a final diagnosis result.

The server controller 210 first outputs a result of diagnosis of thestate or fault of the home appliance and the fault cause through theserver output device 270 (S410). Here, when a plurality of fault causesexist, the server controller 210 may display the fault causes in a list.When one of the displayed fault causes is selected and input, the servercontroller 210 outputs a solution to the fault cause (S420).

The server controller 210 may transmit the diagnosis result via an emailor message using a registered email address or telephone number of theuser (S440).

Here, a counselor of the service center 200 may check the diagnosisresult displayed on a screen on the server output device 270. Thecounselor of the service center 200 may provide voice guidance on thedisplayed cause and solution to the user connected through a telephone.The counselor of the service center 200 may also perform a procedure forscheduling an appointment for a service technician to visit the user'shome according to the cause and solution.

When the solution includes dispatching of a service technician, theserver controller 210 may transmit the diagnosis result to the terminalof the service technician (S440, S450).

FIG. 9 is a flow chart illustrating a diagnostic method using an errorcode among product information in a home appliance diagnostic system ofthe present invention.

The diagnoser 260 prepares reference data or fault diagnostic dataaccording to smart diagnosis version and model information and firstchecks an error code among diagnostic data included in productinformation to perform fault diagnosis.

A door error among errors of a plurality of error codes occurs dependingon the state of the door of the laundry treatment machine. When the dooris not closed, when the door is not locked, or when the door is opened,a door error occurs since the laundry treatment machine cannot performoperations according to a set course.

When a door error occurs, the diagnoser 260 performs fault diagnosisbased on the type of supplied water, water temperature, and the like.

The door should be opened when laundry is put into the laundry treatmentmachine and be closed when the laundry treatment machine startsoperation. Thus, a door error occurs only when an operation such aswashing, rinsing, or spin-drying is being performed, whereas no doorerror occurs in the preliminary step or the completion step since thedoor may be opened normally at the preliminary or completion step.

When a door error has occurred at the preliminary or completion step,the diagnoser 260 may determine that a program error has occurred.

When a door is opened during an operation such as washing, rinsing, orspin-drying, the diagnoser 260 determines that a door error has occurredsince the door should be closed during the operation and determineswhether the supplied water is cold or hot and performs fault diagnosisusing the temperature of the water in each case where the supplied wateris cold or hot water.

The operation of the home appliance is divided into a plurality ofoperation steps, and information about an operation step that the homeappliance has performed last among the plurality of operation steps isstored in state information.

For example, the state information includes information about anoperation step that the laundry treatment machine has performed lastamong a preliminary step, a washing step, a rinsing step, a spin-dryingstep, a drying step, and a completion step into which the operation ofthe laundry treatment machine is divided before the laundry treatmentmachine performs specified operations. Here, each step may be classifiedinto sub-steps. For example, the washing step may be further classifiedinto rough washing, soaked washing, main washing, and finishing washingsteps and the rinsing step may be further classified into first-timerinsing, second-time rinsing, third-time rinsing, and fourth-timerinsing steps. The first-time rinsing step may also be furtherclassified into a drainage step, a brief spinning step, a main spinningstep, and a water supply step. The state information includesinformation about such finely classified operations of the homeappliance.

Here, the state information may be about 1 byte long and may includeinformation about each of about 60 to 64 operations into which the stepsof the home appliance are divided.

Here, the values “0” to “5” of state information may indicate operationsof a preliminary step, specifically, the value “0” may indicate aninitialization step, “2” a stop step, “3” a course scheduling step, “4”a freezing detection step, and “5” a laundry quantity detection step.The values “55” and “56” may indicate drying steps, specifically, thevalue “55” may indicate a hot air drying step and “56” a cool-down step.

A temperature of the tub, which is measured when the operation starts,i.e., when water supply starts, is stored as a first wash watertemperature “Water Temperature W0”. The first wash water temperature isnot measured when water supply is resumed after being stopped.

On the other hand, a temperature of the tub, which is measuredimmediately after the initial water supply is completed, is stored as asecond wash water temperature “Water Temperature W1”. The temperature ofthe tub can be considered the temperature of the wash water since thetemperature of the tub varies with the temperature of the wash waterwhen water supply is performed.

The wash water temperature may be used as the water temperaturedescribed above and a rinse water temperature may be used in the rinsingmode.

The type of the supplied water, i.e., whether the supplied water is coldor hot water, may be determined through the water temperature.

The diagnoser 260 diagnoses a fault of the home appliance using suchdata items included in the product information and derives a solution tothe fault.

As shown in FIG. 9, when an error code for the door has occurred (S480),the diagnoser 260 derives a fault cause and a solution using the stateinformation and the water temperature. The diagnoser 260 checks othererror codes when the error is not a temperature error (S560).

The diagnoser 260 checks whether the state information indicates apreliminary operating state in association with the door error (S490).For example, when the state information is one of 0 to 5, the diagnoser260 determines that the home appliance has not yet started operation andthat the home appliance is in a data input step, an initialization step,or a basic value setting step.

When the state information does not indicate a preliminary operatingstate, i.e., when the home appliance is in operation, the diagnoser 260diagnoses a fault cause as door air (S500) and derives a solutionrequesting the user to check the door's closed state, check whether thedoor is loose, and check whether the door can be closed (S510).

The derived result is stored and output in the manner described below.

When the user has requested that a service technician be dispatched forthe door error (S520), the server controller 210 performs a setting fordispatching a service technician and performs a procedure for schedulinga corresponding appointment for the service technician to visit the user(S530). When the user has not requested that a service technician bedispatched, the server controller 210 provides the user with guidance onservice technician dispatch.

FIG. 10 illustrates exemplary fault diagnosis results using productinformation in a home appliance diagnostic system of the presentinvention.

As shown in FIG. 10, the server controller 210 generates and outputs atleast one fault diagnosis result for the door error through thediagnosis results of the diagnoser 260 and outputs a solution for eachdiagnosis result.

The server controller 210 outputs a diagnosis result indicating that thecause of the door error is a program error and schedules a servicetechnician to be dispatched or requests the user to check the door'sstate.

Specifically, the server controller 210 provides the user with guidancerequesting the user to check whether the door can be closed normallyafter being raised. The door's state may be fixed through such check bythe user.

When the door is loose, a service technician for repairing the laundrytreatment machine may be dispatched at the request of the user and, whenthe door cannot be closed, whether to dispatch a service technician maybe set according to the request of the user.

When the fault cause and solution are output in the above manner, theserver controller 210 allows the counselor of the service center 200 toprovide guidance on such results to the user connected to the servicecenter 200 over a telephone and performs a corresponding procedure.

As is apparent from the above description, the home appliance diagnosticsystem and method according to the present invention receives a soundsignal output from the home appliance, extracts product information fromthe sound signal, diagnoses fault of the home appliance using datacorresponding to an error code among a plurality of data included in theproduct information, and provides a solution to the fault. Therefore,the user can easily confirm and inspect the state of the home applianceand it is also possible to correctly diagnose the door error. Inaddition, when there is a need to dispatch a service technician, it ispossible to quickly perform a procedure for dispatching the servicetechnician, thereby increasing user convenience and providing acustomized after-sale service suitable for the state of the homeappliance.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

What is claimed is:
 1. A diagnostic method for a home appliancediagnostic system, the method comprising: receiving a sound signaloutput from a home appliance and extracting product information aboutthe home appliance from the sound signal; analyzing the productinformation and determining, when an error code is set in the productinformation, whether the error code corresponds to a door errorassociated with a door of the home appliance; diagnosing fault of thehome appliance by determining, when the error code corresponds to thedoor error, whether the door or a program of the home appliance is outof order using diagnostic data associated with the door among aplurality of diagnostic data included in the product information; andderiving a diagnosis result by deriving a solution corresponding to acause of the door error, the cause being obtained according to the faultdiagnosis.
 2. The diagnostic method according to claim 1, whereindiagnosing the fault of the home appliance includes determining whetherthe error code has occurred before the home appliance performs a setoperation using state information among the plurality of diagnosticdata.
 3. The diagnostic method according to claim 2, wherein diagnosingthe fault of the home appliance includes determining, when the doorerror has occurred during the set operation, that the door error iscaused by abnormality in the door.
 4. The diagnostic method according toclaim 3, wherein deriving the diagnosis result includes deriving asolution requesting at least one of check of a closed state of the door,check as to whether the door is loose, and check as to whether the doorcan be closed.
 5. The diagnostic method according to claim 4, furthercomprising: outputting the diagnosis result and providing a user of thehome appliance with guidance on the output diagnosis result.
 6. Thediagnostic method according to claim 2, wherein diagnosing the fault ofthe home appliance includes determining, when the door error hasoccurred before the set operation, that the door error is caused bymalfunction of the program.
 7. The diagnostic method according to claim6, wherein deriving the diagnosis result includes deriving a solution ofdispatching a service technician for repairing the fault caused by themalfunction of the program.
 8. The diagnostic method according to claim7, further comprising: performing a procedure for scheduling anappointment for the service technician to visit a user of the homeappliance and transmitting the diagnosis result to a terminal of theservice technician.
 9. The diagnostic method according to claim 1,further comprising: transmitting the diagnosis result to the homeappliance or to a contact of a user of the home appliance.
 10. A homeappliance diagnostic system comprising: a home appliance for outputtingproduct information required for fault diagnosis as a sound signal; adiagnostic server for receiving the sound signal, deriving a state, afault, and a fault cause of the home appliance, and deriving, as adiagnosis result, a solution to the fault; and a portable terminal forreceiving the sound signal output from the home appliance andtransmitting the sound signal to the diagnostic server through acommunication network, wherein the diagnostic server determines, when anerror code is set in the product information extracted from the receivedsound signal, whether the error code corresponds to a door errorassociated with a door of the home appliance based on the productinformation, and diagnoses fault of the home appliance by determining,when the error code corresponds to the door error, whether the door or aprogram of the home appliance is out of order using diagnostic dataassociated with the door among a plurality of diagnostic data includedin the product information, and then derives a solution to the fault ofthe home appliance.
 11. The home appliance diagnostic system accordingto claim 10, wherein the diagnostic server determines that the fault ofthe home appliance is caused by at least one of abnormality of the dooror malfunction of the program using state information among theplurality of diagnostic data.
 12. The home appliance diagnostic systemaccording to claim 10, wherein, when the door error is caused byabnormality of the door, the diagnostic server derives a solutionrequesting at least one of check of a closed state of the door, check asto whether the door is loose, and check as to whether the door can beclosed.
 13. The home appliance diagnostic system according to claim 11,wherein, when the door error is caused by malfunction of the program,the diagnostic server derives a solution of dispatching a servicetechnician and performing a procedure for setting an appointment todispatch the service technician.